This invention relates generally to electronic timepiece frequency regulating circuits, and in particular, to effecting regulations of the low frequency timekeeping signal without varying the frequency of the high frequency time standard signal produced by the oscillator circuit.
Heretofore, timepieces of the mechanical variety having a balance wheel oscillator and electronic timepieces having either tuning fork or quartz crystal oscillator circuits have been difficult to adjust when optimum accuracy is required. In each type of timepiece, the adjustment is made directly to the vibrating time standard. Thus, when a quartz crystal oscillator circuit is utilized, the oscillating frequency of the oscillator circuit is regulated by inserting a variable capacitor into the oscillator circuit and changing the value of the capacitor in order to adjust the resonant frequency of the oscillator circuit. Alternatively, the vibrator itself, e.g., balance wheel, tuning fork, quartz oscillator or the like, is altered or means are added thereto to change the frequency at which some vibrates. Such methods of regulating the high frequency time standard signal produced by the oscillator circuit have been found to be less than completely satisfactory.
It is noted that when additional circuit elements and/or mechanical elements are added to a vibrator, the stability of the oscillator circuit is reduced. Additionally, since the resonant frequency must be selected within narrow limits to permit regulation thereof, the manufacturing of the time standards utilized in the oscillator circuit require constant attention and high precision, thereby increasing the manufacturing costs of the electronic timepieces utilizing such time standards. Accordingly, it is desired to include a frequency regulating circuit in an electronic timepiece for varying the division ratio of the divider circuitry to thereby regulate the frequency without affecting the oscillator circuit.